Turbine diaphragm



NW? 23, 39% J. L. RAY

TURBINE DIAPHRAGM Filed Sept. 18, 1946 INVEPITOR ATTORNEY Patented Nov.21, 1950 IUNITED STATES PATENT OFFICE TURBINE DIAPHRAGM James L. Ray,Long Beach, Calif., assignor to Allis-Chalmers Manufacturing Company,Milwaukee, Wis., a corporation of Delaware Application September 18,1946, Serial No. 697,799

' temperatures, and especially such temperatures as obtain in gasturbines, difficulties are encountered by reason of the relatively largeexpansion of the diaphragm means when subjected 'to such hightemperatures, and it is an object of the invention to provide new andimproved dia-' phragm means which will obviate these difliculties.

Another object of the invention is the provision of diaphragm means inwhich is embodied new and improved means for centering the diaphragmmeans while at the same time permitting expansion and contractionthereof, and, more specifically, permitting large expansion andcontraction which occurs by reason of a large range of temperatures.

Other objects will appear hereinafter as the description of theinvention proceeds.

The novel features of the invention and how the objects are attainedwill appear from this specification and the accompanying drawing showingone embodiment thereof and forming a part of this application, and allthese novel features are intended to be pointed out in the claims. a

In the drawing, Fig. 1 is a fragmentary, longitudinal half-sectionalview of a gas turbine embodying the invention; and

Fig. 2 is a cross-sectional view, partly fragmentary, taken on the lineIIII looking in the direction of the arrows.

The turbine illustrated comprises a stator It and a rotor II. The-statorincludes a cylinder or casing I2 surrounding the rotor. The rotor IIincludes a spindle or shaft I3, the center line of which is indicated bythe line C. L.

Theshaft I3 is here shown as carrying wheels I4, I5, each of which isprovided at its outer periphery with a set of radially extendingcircumferentially spaced vanes or blades I5, I1.

I Disposed between the wheels I4, I5 and supported across the spacebetween the shaft I3 and the stator casing I2 is diaphragm means I8. Thediaphragm means I8 comprises a 4 Claims. Cl. 253-48) plurality ofconcentric ring means, here shown as two principal ring means I9, 20.The outermost ring means I9 has its outer annular periphery constructedand arranged for lost motion connection with the stator, the outerperiphery as here shown, being adapted to fit slidably in an annularrecess 2I in a wall portion of the stator casing I2. Thesmaller ringmeans 20 has its outer annular periphery constructed and arranged forlost motion connection with the outermost ring means, the outerperiphery of the smaller ring means 20, as here shown, being adapted tofit slidably in an annular recess 22 in the inner periphery of theoutermost ring means I9. The inner periphery of the innermost ring means(in this instance the smaller ring means 20, next adjacent the outermostring means I9) carries in any suitable way, shaft seal ring means 23 ofany desired and suitable type, cooperating with the surface portion 24of the shaft I3 to prevent leakage of gas, at the shaft, from the leftside to the right side of the diaphragm means I8.

Centering means is provided for maintaining the plurality of ring meanscomprised in the diaphragm means I8 coaxial with the shaft I-3. Thecentering means may include a plurality of radial keys, abutments, pins,or other suitable means. In this instance a plurality of radial pins isshown, as will more fully appear.

Considering first the centering means associated with the outermost ringmeans I9. The outermost ring means I9 has a. set of a plurality ofcircumferentially spaced radial holes 25 extending thereinto from theouter periphery of the ring means, the number of holes being here shownas six in number; and the turbine casing I2 has a set of a plurality ofradial holes 29 extending through the casing wall, the holes 25 being ofthe same size and number as the holes 25. When the parts are assembled,the holes 26 of the set in the turbine casing I2 are in radial alinementwith the holes 25 of the set in the outermost ring means I9, and thepairs of alined holes of the sets has slidably disposed therein, pins21.

The smaller ring means 20 has a set of a plurality of circumferentiallyspaced radial holes 28 etxending thereinto from its outer periphery, thenumber of holes 28 being here shown as six in number; and the outermostring means I9 has a set of a, plurality of radial holes 30 extendingthereinto from the inner periphery, the holes 30 being of the same sizeand number 9 the ho es 2.8 The holes 35 of the set in the innerperiphery of the outermost ring means I9 are in radial alinement withthe holes 28 of the set in the outer periphery of the smaller ring means20, and when the parts are assembled, the pairs of alined holes of thesets have slidably disposed therein, pins 3I As here shown, the holes 30of the set in the inner periphery of the outermost ring means I9 are inradial alinement with the holes 25 of the set of holes in the outerperiphery of the outermost ring-means I9. Furthermore, in the embodimentshown the pins SI and the holes with which they cooperate, are ofsmaller diameter than the pins 2'! and the holes with which theycooperate.

The anular recess 2I in the turbine casing I2 is sufficiently deep toleave annular clearance space 48 with respect to the outer periphery ofthe outermost ring means I9 such that the outermost ring means mayfreely expand, and the annular recess 22 in the inner periphery of theoutermost ring means I9 is sufliciently deep to leave annular clearancespace 49 such that the smaller ring means 2 9 may freely expand, whenthe parts are subjected to the respective maximum temperatures.

Radially outward movement of the pins 21 may be limited by anysuitablemeans, in this instance by plugs 32 screwed into enlarged outerends of the holes 26. The pins 21 and the pins 3I are of such lengththat a desired suitable amount of radial clearance will be left when thering means I9 and the ring means 2|] have expanded to the maximumamount.

Desirably, an annular recess 33 is formed at the junction between theholes 25 and the holes 30; and an annular recess 34 is formed at thebottoms of the holes 28. The recesses 33 and 34 provide run-outs for theboring and reaming tools, making it unnecessary to bore and ream clearto the bottom of the respective holes.

As here shown, the outermost ring means I 9 is made in two semi-circularsegments fastened together by machine screws 35 cooperating with flanges36, 3'! extending laterally from the respective segments. In like mannerthe smaller ring means 29 may be made in two semi-circular segmentsfastened together by machine screws 38 cooperating with flanges 39, 40extending laterally from the respective segments. The turbine casing I2may be made in halves having flanges M, 42 held together by bolts andnuts 43.

Gas is adapted to enter an inlet chamber 44 from which it passes throughsuitable nozzles 45 against the blades I6 of the wheel I4. Gasdischarged from the blades I6 passes through nozzles 46 which may beprovided, as here shown, by a plurality of blades interposed in andforming a part of the inner ring means 20. From the nozzles 49 gas isdischarged against the blades I! of the wheel I5, and from thence it maybe discharged, as here shown, to one or more other stages 17 of theturbine.

As the outermost ring means I9 is heated, it is free to expand radially,and when it cools off it is free to contract radially, moving relativelyto the turbine casing in the annular recess 2I, but at all times theaxis of the ring means I9 is maintained coaxial with the shaft I3 by thepins 21. Likewise, the smaller ring means 29 is free to expand radiallywhen heated and free to contract radially when cooled, moving relativelyto the outermost ring means I9, and relatively to the turbine casing I2,in the annular recess 22, but at all t mes the axis of the smaller ringmeans 29 is maintained coaxial with the outermost ring means I9, andhence also coaxial with the shaft I3, by the pins 3|.

The parts may be assembled as follows. Assuming that the upper half ofthe turbine casing I2 has not yet been applied, and that the seal ringmeans 23, which, if desired, may be in segments, has been assembled withthe respective halves of the smaller ring means 20, the halves of thesmaller ring means 20 are placed about the shaft and the halves fastenedtogether with the screws 38. Then the halves of the outermost ring meansI9 are positioned around the smaller ring means 20, the halves of thering means I9 are fastened together by the screws 35, and the pins 3|are inserted, through the holes 25, into the holes 39, 28, the holes 39and holes 28 having been brought into alinement. Then the upper half ofthe turbine casing I2 is positioned on the lower half thereof, and thepins 21 are inserted, through the holes 26, into the holes 25, the holes25 having been positioned in alinement with the holes 26. The pins 21,as hereinbefore mentioned, are prevented from moving radially outwardlyby applying the plugs 32.

While the holes 25 and 30 could be made of the same diameter and asingle pin could be substituted for the two pins 21 and 3I, theembodiment illustrated is preferred because the use of two pins 2! and3i of different diameters facilitates manufacturing operations. Forexample, the holes 30 and 28, can be line reamed with a small reamerduring assembly of ring means I9 and ring means 29, without affectinghole-2 5. Subsequently, hole 25 and hole 26 may be line reamed togetherwhen assembling ring means I9 and cylinder I2. It would be possible butmore complicated to temporarily aline cylinder I2, ring means I9, andring means 29 and line ream clear through all three of these parts forthe same size of pin. While the same final result would be achieved, theuse of two pins of different diameters is preferred for the reasonshereinbefore stated.

From the foregoing it will be apparent to those skilled in the art thatthe illustrated embodiment of the invention provides a new and improvedturbine diaphragm and accordingly accomplishes the objects of theinvention. On the other hand, it will also be obvious to those skilledin the art that the illustrated embodiment of the invention may bevariously changed and modified, or features thereof singly orcollectively, embodied in other combinations than those illustratedwithout departing from the spirit of the invention, or sacrificing allof the advantages thereof, and that, accordingly, the disclosedembodiment is illustrative only, and the invention is not limitedthereto.

It is claimed and desired to secure by Letters Patent:

1. A turbine constructed and arranged for operation by elastic fluid,comprising: a rotor shaft; an annular wall surrounding said shaft andleaving a space between said wall and said shaft; diaphragm meansincluding a plurality of concentric ring means across said space, theoutermost of said ring means having a lost motion connection with saidannular wall, and having a lost motion connection with adjacentsmallerring means; first centering means for maintaining said outermostring means coaxial with said shaft while permitting free expansion andcontraction of said outermost ring means in all radial directions, saidfirst centering means including a first plurality of sets ofcircumferentially spaced holes in said outermost ring means and saidwall respectively, holes of said respective sets being in radialalinement and a plurality of first members cooperating with alined setsof said first plurality of sets; and second centering means formaintaining said smaller ring means coaxial with said shaft whilepermitting free expansion and contraction of said smaller ring means inall radial directions, said second centering means including a secondplurality of sets of circumferentially spaced holes in said outermostring means and said smaller ring means respectively, holes of saidrespective sets being in radial alinement and in radial alinement withalined holes of said first plurality of sets, and a plurality of secondmembers, separate from said first members, cooperating with alined setsof said second plurality of sets.

2. A turbine constructed and arranged for operation by elastic fluid,comprising: a rotor shaft; an annular wall surrounding said shaft andleaving a space between said wall and said shaft; diaphragm meansincluding a plurality of concentric ring means across said space, theoutermost of said ring means having a lost motion connection with saidannular wall, and having a lost motion connection with the adjacentsmaller ring means; first centering means for maintaining said outermostring means coaxial with said shaft while permitting free expansion andcontraction of said outermost ring means in all radial directions, saidfirst centering means including a first plurality of sets ofcircumferentially spaced holes in said outermost ring means and saidwall respectively, the holes of each set being in radial alinement;second centering means for maintaining said smaller ring means coaxialwith said shaft while permitting free expansion and contraction of saidsmaller ring means in all radial directions, said second centering meansincluding a second plurality of sets of circumferentially spaced holesin said outermost ring means and said smaller ring means respectively,the holes of each set being in radial alinement; said first plurality ofsets comprising, sets which are radially alined with sets of said secondplurality of sets; and said first and second centering means includingmembers cooperating with alined sets of said first and second pluralityof sets.

3. A turbine constructed and arranged for operation by elastic fluid,comprising: a rotor shaft; an annular wall surrounding said shaft andleaving a space between said wall and said shaft; diaphragm meansincluding a plurality of concentric ring means across said space, theoutermost of said ring means having a lost motion connection with saidannular wall, and having a lost motion connection with adjacent smallerring means; first centering means for maintaining said outermost ringmeans coaxial with said shaft while permitting free expansion andcontraction of said outermost ring means in all radial directions, saidfirst centering means including a first plurality of sets ofcircumferentially spaced holes in said outermost ring means and saidwall respectively, the holes of each set being in radial alinement and aplurality of first members cooperating with alined sets of said firstplurality of sets; and second centering means for maintaining saidsmaller ring means coaxial with said shaft While permitting freeexpansion and contraction of said smaller ring means in all radialdirections, said second centering means including a second plurality ofsets of circumferentially spaced holes in said outermost ring means andsaid smaller ring means respectively, the holes of each set being inradial alinement with and of smaller diameter than the holes of saidfirst plurality of sets, and a plurality of second members, separatefrom said first members, cooperating with alined sets of said secondplurality of sets.

4. A turbine constructed and arranged for operation by elastic fluid,comprising: a rotor shaft; an annular wall surrounding said shaft andleaving a space between said wall and said shaft; diaphragm meanssupported across said space, said diaphragm means including a pluralityof concentric ring means, the outermost of said ring means having a lostmotion connection in all radial directions with said annular wall, andhaving a lost motion connection in all radial directions with theadjacent smaller ring means; and centering means for maintaining saidplurality of ring means coaxial with said shaft while permitting freeexpansion and contraction of said plurality of ring means radially inall directions relatively to each other and relatively to said annularwall, said centering means including a plurality of circumferentiallyspaced members cooperative with a plurality of sets of circumferentiallyspaced holes in said plurality of ring means and said wall respectively,the holes of each set being in radial alinement with the holes of theother sets.

JAMES L. RAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,873,743 Doran Aug. 23, 19322,080,425 Lysholm May 18, 193'? 2,258,792 New Oct. 14, 1941 2,304,994Franck Dec. 15, 1942 2,447,942 Imbert et al Aug. 24, 1948

